STUDY BEHAVIOUR OF DIFFERENT ELEMENTS IN ANSYS FINITE ELEMENT

SOFTWARE

ZAIDI BIN ZOLKEFLE

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

SUPERVISOR DECLARATION

“I hereby declare that I have read this thesis and in my opinion this thesis is

sufficient in terms of scope and quality for the award of the degree of Bachelor of

Mechanical Engineering (Structure and Materials)”

Signature : ………………………………………

Supervisor’s Name : PROF. MADYA AHMAD RIVAI

Date : ………………………………………

STUDY THE BEHAVIOUR OF DIFFERENT ELEMENTS IN ANSYS FINITE

ELEMENTS SOFTWARE

ZAIDI BIN ZOLKEFLE

This Thesis Is Submitted In Partial Fulfillment of Requirement for the Bachelor Degree

of Mechanical Engineering (Structure & Material)

\

Faculty of Mechanical Engineering

Universiti Teknikal Malaysia Melaka

JUNE 2015

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DECLARATION

“I hereby declare that the work in this thesis is my own except for summaries

and quotations which have been duly acknowledgement”

Signatures : ………………………………

Name of Authors : ZAIDI BIN ZOLKEFLE

Date : ………………………………

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Especially for my father, Zolkefle Bin Haron and my mother,

Zarena Bte. Abd. Rahman

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ACKNOWLEDGEMENT

First of all, I would like to give my sincere thanks to my supervisor,

Professor Madya Ahmad Rivai, for his guidance, inspiring motivation and helps

during the supervision of this project. I have been very fortunate to be the

chosen student under his guidance. His constant voice of advices and

constructive criticism, especially in writing this thesis has been my source of

inspiration.

I would like to thanks my parents for give me a moral support and spirit

to complete my final year project report. I would also like to acknowledge with

much appreciation to staff of Mechanical Laboratory, who gave the permission

to conduct the experiment for this project. They have given so much

cooperation to me during three-point bending test.

Lastly, I would like to say thank you to all Mechanical Faculty’s staff

especially Jawatankuasa Projek Sarjana Muda (JKPSM) which have provided

useful guidance and lots of information in order to write a good final thesis and

some tips in preparation for seminar presentation.

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ABSTRACT

Finite Element Analysis (FEA) is widely used in engineering field, especially

in aircraft and structure engineering. Generally, it is a numerical method for solving

engineering problems with complicated geometries, loadings and material properties.

There are software that could be used to model and analyse FEA problems, such as

Abaqus. ANSYS software is usually used to perform analysis on Computational

Fluid Dynamics (CFD. The objective of this project is to study and investigate the

capability of ANSYS in modelling and analysing structural problems by using

different elements which are one-dimensional (1D), two-dimensional (2D) and three-

dimensional (3D) elements. The validation and verification of the result will be done

by comparison of analysis from ANSYS with experimental data, theoretical

calculation and comparing the analysis result from other software. From the analysis,

the distinction of the result from ANSYS with analysis of other software, theoretical

calculation and experimental data was not too high with the percentage of error of 1

percent to 10 percent. So, ANSYS can be an effective platform to carry out structural

modelling and analysing in Finite Element Analysis.

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ABSTRAK

Analisis Unsur Terhingga (FEA) telah digunakan secara meluas dalam bidang

kejuruteraan, terutamanya dalam kejuruteraan pesawat dan kejuruteraan struktur.

Secara ammya, ia adalah satu kaedah berangka bagi menyelesaikan masalah

kejuruteraan dengan geometri yang rumit, bersama beban dan sifat bahan yang

tertentu. Terdapat beberapa perisisan komputer yang boleh digunakan untuk

memodel dan menganalisa masalah FEA, seperti ABAQUS. Perisian ANSYS

biasanya digunakan secara meluas untuk melakukan analisis berkenaan masalah

Pengkomputeran Dinamik Bendalir (CFD). Projek ini bertujuan untuk mengkaji dan

mempelajari keupayaan perisian ANSYS dalam permodelan dan menganalisis

masalah struktur dengan menggunakan elemen yang berbeza iaitu elemen satu

dimensi (1D), elemen dua dimensi (2D) dan elemen tiga dimensi (3D). Pengesahan

dan pengukuhan akan keputusan yang telah dianalisis menggunakan perisian ANSYS

akan dibandingkan dengan keputusan dariapada ujikaji, pengiraan teori dan

perbandingan bersama hasil analisis daripada perisisan yang lain. Merujuk kepada

hasil analisis, perbezaan keputusan perisian ANSYS dengan platfom yang berbeza

tidak terlalu tinggi dengan peratusan perbezaan hanya dalam 1 sehingga 10 peratus.

Jadi, ANSYS boleh menjadi platfom yang berkesan untuk menjalankan permodelan

dan analisis terutama sekali dalam Analisis Unsur Terhingga (FEA).

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CONTENT

CHAPTER TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENT vii

LIST OF TABLES x

LIST OF FIGURES xii

LIST OF GRAPHS xv

NOMENCLATURE xvi

APPENDIX xviii

CHAPTER 1 INTRODUCTION

1.1 Background of Project 1

1.2 Problem Statement 3

1.3 Objective 3

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1.4 Scope of Projects 4

CHAPTER 2 LITERATURE REVIEW

2.1 Project Review 5

2.2 Structural Analysis 6

2.2.1 Safety Assessment in Structural

Analysis 7

2.2.2 Phase In Structural Engineering 7

2.2.2.1 Planning Phase 8

2.2.2.2 Preliminary Structural Design 8

2.2.2.3 Estimation of Load 9

2.2.2.4 Structural Analysis 9

2.2.2.5 Revised Structural Design 9

2.2.3 Classification ofStructural Analysis 9

2.2.3.1 Tension Structure 10

2.2.3.2 Compression Structure 10

2.2.3.3 Shear Structure 11

2.2.3.4 Bending Structure 12

2.3 Method of Analysis 13

2.4 Bending Test 13

2.5 Finite Element 15

2.5.1 Finite Element Analysis (FEA) 15

2.6 ANSYS Finite Element Software 16

2.6.1 ANSYS Mechanical APDL 17

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2.6.2 ANSYS Workbench 18

2.6.3 Solid-Work 18

2.7 Modelling 19

2.7.1 1D Structural Modelling 19

2.7.2 2D Structural Modelling 20

2.7.3 3D Structural Modelling 20

2.7 Analysis 21

CHAPTER 3 METHODOLOGY

3.1 Introduction 22

3.2 Project Flow Chart 23

3.3 One-Dimensional Analysis 24

3.4 Two-Dimensional Analysis 27

3.5 Three-Dimensional Analysis 31

CHAPTER 4 RESULTS

4.1 Validation of One-Dimensional Element 36

4.2 Validation of Two-Dimensional Elements 38

4.3 Validation of Three-Dimensional Elements 39

CHAPTER 5 ANALYSIS AND DISCUSSION

5.1 Introduction 42

5.2 One-Dimensional Analysis 43

5.3 Two-Dimensional Analysis 45

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5.4 Three-Dimensional Analysis 48

5.5 Discussion

5.5.1 One-Dimensional Element 52

5.5.2 Two-Dimensional Elements 53

5.5.3 Three-Dimensional Elements 53

CHAPTER 6 CONCLUSION AND RECOMMENDATION

6.1 Conclusion 55

6.2 Recommendation 56

REFERENCES 57

APPENDIX 60

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LIST OF TABLES

TABLE TITLE PAGE

3.1 Record of equipment for 3-point bend testing 26

3.2 Material properties of test specimen 27

3.3 Mechanical properties of cantilever beam 28

3.4 Material properties of I-Beam structure 32

4.1 Results of strain distribution for 3kN load from

Experiment 36

4.2 Results of stress distribution on nodes from

Equation 3.1 37

4.3 Result of stress distribution analysis between nodes in

ANSYS software analysis 38

4.4 Comparison of results between 5m and 10m element size 39

4.5 Comparison of stress and deformation of beam on

Solid-Work analysis 41

4.6 Comparison stress distribution results between

experiment data and ANSYS analysis 41

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5.1 Comparison stress results between experiment and

ANSYS analysis 44

5.2 Relation of error between results of ANSYS software

And 3-point bending test 46

5.3 Comparison of result between theoretical calculations

and ANSYS analysis with 5 meter element size 47

5.4 Comparison of result between theoretical calculations

and ANSYS analysis with 5 meter element size 47

5.5 Comparison of results between Solid-work analysis

and ANSYS analysis with tetrahedrons element method 49

5.6 Comparison of results between Solid-work analysis

and ANSYS analysis with Hex-Dominant element method 49

5.7 Percentage difference of results comparison between

Solid-Work and ANSYS with different element methods

for stress and deformation results 52

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LIST OF FIGURES

FIGURES TITLE PAGE

1.1 3 Point Bend Analysis 2

2.1 Phase of a Typical Structural Engineering 8

2.2 Tension Structures 10

2.3 Column structure 11

2.4 Shear Wall Structural Analysis 12

2.5 Bending Structures 12

2.6 Bend testing of a rectangular bar under a) three-point

bend and b) four-point bend 16

2.7 Example of bend testing under 3 point bend experiment 17

2.8 1D (line), 2D (plane), and 3D (solid) elements 16

2.9 ANSYS Workbench interface for static structural 18

2.10 1D Beam Element 19

2.11 2D (plate) structural element 20

2.12 3D element structure 21

3.1 Project flow chart for PSM 23

3.2 Modelling 1-D structural beam on ANSYS 24

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3.3 Aluminium beam with nodal points 25

3.4 Experiment setup for 3-point bending 23

3.5 Schematic diagram of experiment setup 26

3.6 Schematic diagram of cantilever beam 28

3.7 Applying the same element method

(quadrilateral dominant) different element size of

structural beam. 29

3.8 Modelling of structural beam and moment force

applied to beam 29

3.9 Schematic diagram of I-Beam structure with specific

Dimension 32

3.10 The I-Beam modelling method by using A) Solid-Work

and B) ANSYS software 32

3.11 Different method of elements was applied to

I-Beam structure A) Tetrahedron, B) Hex-dominant

elements 32

3.12 Stress application on the structure on A) Solid-Work,

and B) ANSYS 34

4.1 Point of reference point on 3-D structural analysis 40

5.1 Beam deflection analysis on ANSYS APDL 43

5.2 Analysis results on ANSYS software of two-dimensional

cantilever beam 46

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5.3 Structural Analysis results in ANSYS software on

I-Beam structure 48

5.4 Structural Analysis results in Solid-Work software

on I-Beam structure 49

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LIST OF GRAPHS

GRAPH TITLE PAGE

5.1 Comparison between stress distribution result from

experiment data and ANSYS analysis on each nodes 44

5.2 Stress distribution results comparison of Solid-Work

analysis results with ANSYS analysis result on

different type of elements, Tetrahedron and

Hex-Dominant methods 50

5.3 Deformation of beam results comparison of Solid-Work

analysis results with ANSYS analysis result on

different type of elements, Tetrahedron and

Hex-Dominant methods 51

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NOMENCLATURE

FE Finite Element

FEA Finite Element Analysis

FEM Finite Element Method

DSA Direct Stiffness Method

MSA Matrix Stiffness Method

CAD Computational Aid Diagram

CFD Computational Fluid Dynamics

GUI Graphics User Interface

APDL ANSYS Parametric Design Language

Emag Electromagnetic

Props Properties

Prosproc Proprocessor

1D One-Dimensional

2D Two-Dimensional

3D Three-Dimensional

3PB Three Point Bend

m Meter

N Newton

k Kilo ( X 103)

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Pa Pascal

G Giga (X 109)

M Mega (X 106)

σ Stress

σx Normal Stress

E Modulus of Elasticity

σm Moment of Stress

I Moment of Inertia

ε Strain

εx Normal Strain

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APPENDIX

NO. TITLE PAGE

1 GANTT CHART PSM I 60

2 GANTT CHART PSM II 61

CHAPTER 1

INTRODUCTION

1.1 Background of Project

Finite Element Analysis (FEA) initially developed in 1943 by R. Courant, whom

responsible on THE RITZ method by relation of numerical analysis and minimization

variation calculus to obtain approximate solutions to vibration systems (Khairul S. &

Mariani Idroas, 2006). Chandrupatla & Belegundu (2012) state that for expositions

convenience, structural “Finite Element” may be divided into four generations that last

from 10 to 15 years. There are some evolutions of FEA of Matrix Structural Analysis

(MSA) into Direct Stiffness Method (DSM) from 1934 to 1970.

Started from the writer, M. J. (Jon) Turner at Boeing over 1950 to 1962, he

generalized and perfected the DSM and forcefully got Boeing to commit resources to it

while other companies were mired into the Force Method. Then, in addition to Turner,

major contribution to current practice include, B. M. Irons, inventors of ISO-parametric

models, shape functions, and frontal servers, R. J. Melosh, who recognize the Rayleigh-

Ritz link and synchronized the variation deviation of stiffness elements, and E. L.

Wilson, who developed the first open source FEM software (Boeraeve P., 2010).

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Then, M. J. Turner, R. W. Clough,, H. C. Martin, and L. J. Topp established a

broader of numerical analysis papers in “STIFFNESS AND DEFLECTION OF

COMPLEX SRTUCTURES”. Early 70’s, FEA was generally used in automotive,

defense, aeronautics and nuclear industries. With the increasing of technologies level,

FEA has been developed to an incredible precision for all kinds of parameters. FEM has

become the most powerful tool for the numerical solution of a wide range of engineering

problems. It can analysis in structures of heat flux, fluid flow, magnetic flux and

complex problems (Chandrupatla and Blegundu, 2012).

Figure 1.1 shows the example of analysis by using Finite Element Analysis

(FEA) on three-point bending test. It indicate the stress distribution towards the whole

beam.

Figure 1.1: 3 Point Bend Analysis

(Source: Erickson, et. Al (2010))

Nowadays, Finite Elements Analysis is used to express the mechanical behaviour

of a structure in engineering problems. There are three types of elements in finite

element that are 1D (one-dimensional), 2D (two-dimensional) and 3D (three-

dimensional) elements. For 1D, it is the simplest element, although lacking in their

ability to make modelling on complex structure. 1D commonly uses as a line modelling

to analyse any engineering problems with simple boundary condition and material

properties. 2D elements and 3D elements provide more details and even more

sophisticated results which require more complexity modelling on the structures. But,

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the ability to gain the results on the Finite Elements also depends on the structures of the

elements and the capability of the computer itself to read the element structures.

1.2 Problem Statement

There are many engineering software that has the ability to model or analyze any

engineering problems. In performing structural analysis, especially for Finite Element

Analysis, there are software that capable to conduct modelling and analyzing such as

MSC Patran Nastran, ABAQUS, and ANSYS. But, in the industries, most of them adopt

MSC Patran-Nastran as the platform to solve structural problems. The application of

ANSYS software mostly covers on the Computational Fluid Dynamic (CFD) analysis.

For the exertion of ANSYS in finite element analysis only establish in late

1970’s where the initial product was to analyze the simulation of fluid flow in

engineering. There have been a deficiency of validation and verification of ANSYS

especially in finite element. This project therefore will review the capability of ANSYS

software to perform the modelling and analyzing of finite element structures.

1.3 Objective

To model appropriately the structural analysis problem in Finite Element Analysis

(FEA) by using ANSYS Software.